Frankfurt, Germany — The cold snap gripped much of Europe, freezing rivers, interrupting barges, and threatening heating sources. But it seemed to invigorate the anti-inequality activists in Germany’s financial capital of Frankfurt. The stalwart protesters there are one Europe’s main surviving – and thriving – Occupy Movement encampments.

Since October, hundreds of residents have been bivouacking in tents in a quaint park directly across from the European Central Bank. Last week, as temperatures plunged to this winter’s low of -20 degrees Celsius (-4 degrees Fahrenheit), a core group of 38 held their ground and slept in their tents – a survival challenge that was both physical and ideological.

"It’s important that at least a few of us stay here to give others strength,’ says Jürgen Harter, the software engineer who is the encampment superintendent of sorts, repairing cables, providing water, putting up tents, fine-tuning the logistics of a 50-or-so-tent village. Mr. Harter says he is fighting for a society that is more humane and less ruled by the power of consumption and money. "And for that, it’s worth it to fight – and to freeze," he says.

While the spectacular rise of the worldwide Occupy movement has been followed by its withering away in much of the world, Occupy Frankfurt has established itself as a peaceful, accepted voice – a testimony, some say, to the tradition of tolerance and openness of this old city of commerce.

When police broke up the Berlin camp last month, the Frankfurt camp gained visibility. This week people traveled to Frankfurt from Spain and the Netherlands to get some occupy know-how. Proudly, Harter talks of "occupy tourism."

Squeezed between the banks’ shimmering glass and steel towers and the city's opera house, theater, and posh designer stores, the occupiers are a reminder of a hidden side of this wealthy city. "This location is part of our identity," says Harter, who says he has camped there for the better part of the past four months despite living just a few subway stops from the encampment.

"Nobody is afraid of us. We’re not aggressive. We reject violence. We don’t want to verbally aggress anybody. The bankers who work here are also human beings," Harter says.

This fall, Frankfurt’s Occupy camp was a haven for discussions – on capitalism, education, and culture. But then critics started complaining that the group had no focus anymore, no real mission. Movement supporters argue that the movement’s raison d’être lies in the sheer power of its presence.

For now, the main battle is to survive the cold. On the frigid day I visit the camp, white frost has wrapped the camp in an eerie quiet. A string of protest signs swing in the air, the only visible signs of life. "Euroland will soon be over," one sign reads. "You occupy the money, we occupy the world," another says. "Break the dictatorship of financial markets!’

Braving the wind, Harter inspects the campsite. A few weeks ago the ground was littered with cables. Harter put them all away for safety. The cold made the water pipes he installed freeze. He wants to insulate them. "It looks like we’re going to be here for the long haul," he says. "Maybe one, two years."

Harter goes about slapping shoulders, sharing jokes. "Come on, the sun is shining!" he tells a grumpy-looking man. Gas isn’t working, somebody complains. "I promise," he reassures, "you’ll get gas. You know I have connections!" His voice radiates confidence and everyone is welcome. Every day local bakeries deliver leftover rolls to the camp’s mess, a wide, spacious tent equipped with a kitchen. Neighborhood residents come and cook. Because the water pipes have frozen, campers get water from the opera house, just across the street – 100 liters a day.

One of the biggest benefits is the human exchange, the protesters say – the things protesters and observers learn just by meeting and talking with each other. There are, for example, the investment banker Harter got to know, who confessed that in spite of the money and power he had, he felt lonely, and the prominent people who take the time to stop by after a nearby fundraiser. Often people tell Harter, "I couldn’t do it, but go on!"

The Frankfurt occupy-ers do not expect the world to change overnight. Even if the movement dies, as it already has in many cities, they see the mere fact that US President Obama mentioned economic unfairness in his State of the Union speech in January as a sign the movement has had an impact.